Dog bolting

Hi, I have a couple of questions that I hope kind internet folk can help with because I’m finding mixed answers online.

We have an 18 month year old adopted cockapoo.

We are doing lots of training off the leash, but we can’t shake the habit he has of BOLTING when he sees another person or dog.

His recall is getting there, 9/10 times he’ll come back when called. However on the occasion he bolts without us noticing quickly enough he can be right up to people or dogs in a couple of seconds.

Questions: 1 - if this happens, and he just sniffs the dog or person and comes back immediately (following our command whilst he was bolting towards them), do we reward him because he came back? Or not reward him because he didnt come back when called before meeting the person or dog?

2 - how do you actually curb the instinct to bolt? Good recall, fine, but I’d love to not have to need the recall as much by curbing the impulse. Today for instance I had to interrupt his bolt with recall 4 times in a row for the same dog.

Thanks in advance!